This invention relates to a hydraulic tensioner having a piston and body or sleeve pivotally mounted to a tensioner arm and tensioner housing. More particularly, the present invention relates to a hydraulic tensioner in which a first end of the tensioner is pinned or pivotally mounted to a tensioner arm while the second end of the tensioner body, located opposite the first end, is pivotally mounted to an engine block or other mounting block.
Hydraulic tensioners are typically used as a control device for a chain drive system in an automobile timing system. The tension in the chain can vary greatly due to the wide variation in the temperature and the linear thermal expansion among the various parts of the engine. Moreover, wear to the chain components during prolonged use can produce a decrease in the tension of the chain.
A hydraulic tensioner is conventionally used to take up the slack in the chain that connects the crankshaft to the camshaft in an engine timing system. The typical hydraulic tensioner includes a housing with a bore, a hollow piston slidably received in the bore and a fluid chamber defined by the piston and the bore. The piston is biased in a protruding direction from the bore by a spring. A check valve is also included in the hydraulic tensioner to permit fluid flow from a source of pressurized fluid into the fluid chamber, while preventing back flow in the reverse direction. The piston is typically pressed against a tensioner arm or other device to provide tension to the chain. The force of the chain against the piston in an inward direction is balanced by the resistance force of the fluid and force of the spring in an outward direction.
In one embodiment, the present invention provides a hydraulic tensioner that has a piston pivotally connected to a tensioner arm at one end and a spherically-shaped sleeve or body at the other end. The spherically-shaped body incorporates an oil feed from a ball and socket inlet port. The oil feed inlet port is mounted to an engine head or block.